Taxol two

Taxol two

来源：未知 作者：段豳 时间：2019-03-07 05:01:03

By Joanna Marchant A new cancer treatment more potent than the best-selling cancer drug taxol has produced encouraging results in its first human trials. It could give hope to patients with tumours that have become resistant to taxol. The drug, originally isolated from soil-dwelling micro-organisms called myxobacteria, works in the same way as taxol. In a tumour, cancer cells are dividing out of control. When a cell splits, elastic protein threads draw the chromosomes apart. But epothilone binds to these tubulins and stops the runaway cell division. “Epothilone locks up the tubulin, and stops the chromosomes from being pulled apart,” says Herbie Newell of the Newcastle University Cancer Research Unit. Epothilone appears to be more potent than taxol, so patients do not have to take such a high concentration of the drug. It even works on cancer cells that are resistant to taxol or other treatments. Cells become resistant to taxol when they begin pumping the chemical out of the cell. But the pump can not carry epothilone, so it is much harder for cells to become resistant to it. Hilary Calvert, head of Newcastle University cancer research unit, and his colleagues carried out a phase I clinical trial involving 36 patients being treated at Newcastle General Hospital and Glasgow’s Western General Infirmary. They were aged between 35 and 72, and had a range of cancers, including colorectal, breast and ovary cancer. The disease was halted in about half of the patients, and in five of them, the tumour shrank. “It’s encouraging,” says Newell. The researchers will use the results of the trial to work out which is the best dose to use, and they hope to start the next phase of trials within months. The drug used in the trial was developed by the pharmaceutical company Novartis. But another version of epothilone has been developed by Bristol Myers Squibb. They are testing their drug, in combination with a platinum compound called carboplatin, in clinical trials in Newcastle and Nottingham. This trial is not completed, but according to Calvert, the initial results are similar. “It is very exciting,